I am not saying that we need it in 'English
only'. What I said is this:
'If you speak English, then it is much more preferred if the ACP is in English and the frontend (user-functionality) in your local language'. At least, that is my opinion speaking from experience with vBulletin 3.8 where we use a professional Dutch translation where they decided (rightfully so, because almost everybody in the Netherlands understands English very well) to only translate the frontend in Dutch. However, with vBulletin 3.8 the odd and very irritating/inconvenient thing happens that still a fair amount of phrases appear in Dutch aswell in the ACP
. They can not be divided from each other. So yeah, maybe your switch-idea will work!